This disclosure relates to polycarbonate compositions, and in particular to polycarbonate compositions with low chlorine content, methods of manufacture, and uses thereof.
In the interfacial reaction process of polycarbonate, a carbonyl source such as phosgene is often reacted with a bisphenol A in the presence of an amine catalyst to produce bisphenol-A (BPA) polycarbonate, generating hydrogen chloride (HCl) as a by-product of the reaction. During this reaction, an alkali metal hydroxide, such as sodium hydroxide is generally co-added with the carbonyl source to neutralize the HCl. In that case, sodium chloride as a reaction by-product is dissolved in the aqueous reaction phase and can be removed to trace levels through washing.
The interfacial polymerization of polycarbonate can often result in polycarbonates with a high yellowness index, which can restrict the uses of those polymers from use, for example, in optical applications where a low yellowness index is needed.
Accordingly, an improved method for polymerizing polycarbonate and improved polycarbonate quality are desired.